BOSTON (AP) -- She is a 63-year-old grandmother known as "Mamie," a former stay-at-home mother of five boys, and the cookie-baking wife of the presumptive Republican presidential nominee. But do not be fooled: Republicans and Democrats alike see Ann Romney as an effective political weapon.

The nation is only just beginning to meet the woman Mitt Romney calls "my sweetheart." And as the general election spotlight burns brighter, the Romney campaign is leveraging Ann Romney's natural ability to connect with voters in a way her husband cannot. Already, she is becoming a fundraising powerhouse and chief aggressor in her husband's push to court women.

President Barack Obama's team quietly acknowledges the threat it faces from the Romney who is sweet, unassuming and, at times, unusually willing to share bathroom humor.

To be sure, people who know her well have long viewed her as a political force.

"I realized that at some point the rest of the world was going to take notice, too," said Tagg Romney, 42, the eldest of the Romneys' children. "I think that day has come."

The Romney campaign insists that Ann Romney's intense schedule hasn't significantly changed since December, the height of the primary campaign.

Despite health concerns, she spent the vast majority of those days and nights living in the buses, planes and hotels that define the less glamorous necessities of presidential politics. Her public role in the 2012 presidential contest so far exceeds that of other GOP candidates' spouses.

She is still largely unknown. Quinnipiac University found this week that 64 percent of registered voters don't know enough about her to form an opinion; 25 percent view her favorably compared with 9 percent who do not.

But her profile is growing. And donors and national media outlets alike are clamoring for her time.

Ann Romney headlined a New York City birthday fundraiser this week with Donald Trump that generated more than a half-million dollars for her husband's campaign. The same day she taped a television interview for "Entertainment Tonight." She and her husband also taped their first nationally televised interview as a couple with Diane Sawyer of ABC News.

"Four years ago I said I would never do this again - was pretty emphatic about that. Because it is a stressful time and my hearts go out to anyone that participates in this event," she told Sawyer.

As Mitt Romney often tells supporters, his wife ultimately came around and helped persuade him to run again. She has since embraced a central role in helping the campaign confront her husband's political challenges great and small. In some ways, it's the same supportive role she has always played in a marriage that's spanned 43 years.

But never has her role been this public.

Several times a week on the campaign trail, Mitt Romney shares how they first crossed paths at a Michigan elementary school but didn't start dating until high school. He introduces his wife as his "sweetheart," regularly holds her hand and beams when she introduces him at rallies.

Her mere presence seems to help relax her husband, who sometimes struggles to shed a plastic image. They are not shy about public affection, and he regularly squeezes his wife's hand, even when the cameras are not rolling.

On national television this week, Ann Romney defended her husband's decades-old decision to travel with the family dog strapped in his carrier to the car roof, suggesting that the dog "loved" the experience. She has also become the campaign's leading voice in the struggle to win over female voters.

She took to Twitter for the first time to respond to Democratic strategist Hilary Rosen, who ignited a firestorm last week by saying the millionaire's wife had "never worked a day in her life."

"I made a choice to stay home and raise five boys. Believe me, it was hard work," Ann Romney wrote.

She has since posted no fewer than eight tweets and has more than 38,000 followers.

A Romney staffer has been tasked with handling her media requests for months. But as the demand intensifies, senior advisers concede that they are struggling to balance her time.

There are significant health concerns.

Ann Romney survived breast cancer in 2007 and has been diagnosed with multiple sclerosis, a disease that attacks the central nervous system.

"We travel a lot," said her traveling partner, Susan Duprey, noting that they've been on the road almost continuously since December. Ann Romney shows no visible symptoms of MS, although she must constantly focus on diet and regular exercise.

Aides also work to squeeze in down time. She escapes to their home in California as often as she can to spend time with the family's horses.

"That's the most revitalizing thing that she does," Duprey said. "So we work hard to get her in the company of her horses."

While the Romneys are worth as much as $250 million, her sincerity is sometimes disarming.

She offers cookies she baked from her Welsh grandmother's recipe to reporters on the campaign bus. Aides say she has never used a paid nanny or cook to help raise her children, although she hired a once-a-week house cleaner to help maintain multiple homes. And she jokes about cleaning dirty bathrooms, cooking for a huge family and her own health struggles.

"She is who she is. She doesn't hold back. She says what she thinks. I think that is disarming to people. And people like her quickly when they meet her," Tagg Romney said. He acknowledged that his mother's freewheeling style makes it nearly impossible for aides to control her message, which is typically the mark of the disciplined Romney campaign.

The campaign would not make Ann Romney available for this story.

She raised some eyebrows when she told ABC that "it's our turn now" to assume the presidency.

And a month ago, she made headlines at a Chicago-area campaign event after calling on Republicans to unite behind her husband. While that's eventually what happened, her comment came weeks before the campaign was prepared to issue that message.

"That's my mom. I don't think anyone tries to manage her. I think they recognize that that's not a good idea," Tagg Romney said. "I think that's an asset for us."

Democrats concede that she is an asset, but they're not convinced she'll ultimately make a difference in the battle for the White House.

After all, first lady Michelle Obama is popular as well. That same Quinnipiac poll showed that she's viewed favorably by 60 percent of registered voters.

"Ann Romney is clearly an asset to her husband's campaign. But while she may help get voters to take a look, ultimately Mitt Romney has to seal the deal," said Democratic strategist Karen Finney. "It's Mitt Romney who has to earn voters' trust because it's Mitt Romney they are voting for. And not even her excellent campaign skills can make up for whatever concerns voters may have about whether or not he'd be a good president."